Power driven adjustable seat for automotive vehicle

ABSTRACT

A seat for use in automotive vehicles wherein the seat supporting portion is movable toward and away from a base in response to changes in the inclination of two pairs of links which are articulately connected with the base and the seat supporting portion. One or more helical springs may be attached to the base and to a spindle nut which is movable up and down along an adjusting screw, or the helical springs may be connected to either the links or to the seat supporting portion to thereby change the effective moment applied to the seat supporting portion with changes of the position of the spindle. A motor drive turns the adjusting screw to cause the spindle nut to move between two end positions. Switches reverse the current through the motor drive to change directions of rotation of the adjusting screw when the spindle nut has reached either end position along the latter. A cam follower forming part of a switch rides on a cam surface when the seat supporting portion moves relative to the base. The cam follower drops into a cut out in the cam surface when the seat supporting portion is spaced at a desired distance from the base. To thereby deactivate the motor drive. Shock absorbers can be mounted in the same manner as the helical springs.

United States Patent r191 Sturhan 1 1 POWER DRIVEN ADJUSTABLE SEAT FORAUTOMOTIVE VEHICLE [75] Inventor: Klaus Sturhan, Lemgo, Germany [73]Assignee: Gebr. Isringhausen, Lemgo/Lippe,

Germany [22] Filed: May 5, 1972 [21] Appl. No.: 250,570

[30] Foreign Application Priority Data May 12, 1971 Germany 2123399 52U.S. C1. 248/399, 248/421 511 Int. Cl B60n 1/02 [58] Field of Search...248/399, 162, 157, 421, 378, 248/372, 424, 429; 297/307 PrimaryExaminer-Marion Parsons, Jr. Attorney, Agent, or Fi rmMichael S. Striker[4 1 Jan. 22, 1974 5 7 ABSTRACT A seat for use in automotive vehicleswherein the seat supporting portion is movable toward and away from abase in response to changes in the inclination of two pairs of linkswhich are articulately connected with the base and the seat supportingportion. One or more helical springs may be attached to the base and toa spindle nut which is movable up and down along an adjusting screw, orthe helical springs may be connected to either the links or to the seatsupporting portion to thereby change the effective moment applied to theseat supporting portion with changes of the position of the spindle. Amotor drive turns the adjusting screw to cause the spindle nut to movebetween two end positions. Switches reverse the current through themotor drive to change directions of rotation of the adjusting screwwhen-the spindle nut has reached either end position along the latter. Acam follower forming part of a switch rides on a cam surface when theseat supporting portion moves relative to the base. The cam followerdrops into a cut out in the cam surface when the seat supporting portionis spaced at a desired distance from the base. To thereby deactivate themotor drive. Shock absorbers can be mounted in the'same manner as thehelical springs.

14 Claims, 4 Drawing Figures skrsmzs PATENTEDJAH 22 I874 SHEET 1 BF 2mamas PATENTEDJM 22 1914 saw 2 BF 2 POWER DRIVEN ADJUSTABLE SEAT FORAUTOMOTIVE VEHICLE BACKGROUND OF THE INVENTION known. According to onesuch known system, the seat is mounted on a pair of parallel linksforming a parallelogram lever arrangement, the latter being supported onboth sides of the seats and the resulting arrangement acts to maintainthe horizontal position of the seats as the latter moves towards or awayfrom a fixed base. Ad- I portion of the suspension means, e.g. a tensionspring,

is connected to and moves along the spindle with the rotation thereof.Likewise, a damper or shock absorber may form part of the suspensionsystem. By changing the tension on the springs of the suspension system,the

arrangements have, at least partially, been successful to generatemoments about pivoting points on which the seat is pivotally mounted,which moments counteract the downward forces applied to the seat.

The disadvantage with the above known apparatus is that the weightadjustment must be made by hand by the occupant of the seat, thissometimes being a difficult and inconvenient adjustment. Further, theoccupant of the seat must known his exact weight, 'if the weightadjustment is to be a precise one. Alternately, the occupant may touchan indicator during driving while he is occupying the seat. However, inpractice, difficulties result with both of these approaches and theweight adjustment is still not exactly achieved and, therefore, theoptimal possible comfort of the driver is likewise not obtained. Acomfortable position is, however, important for the prevention ofaccidents, particularly in connection with long distance driving.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a power driven adjustable seat for automotive vehicles whichdoes not possess disadvantages as described above in connection withsimilar seats.

Another object of the present invention is to provide an adjustable seatwhich is simple in construction and economical to manufacture and whichincludes weight adjustments.

A further object of the invention is to provide an adjustable seat whichmakes it possible to change the seat by power driven means, the latterbeing controlled by the occupant of the seat.

A still further object of the present invention is to provide anadjustable seat which incorporates a power driven means with mountingmeansfor maintaining the seat in substantially horizontal positionswhile the seat moves to and away from the base on which it is mounted.

A further object of the invention is to provide a seat of the type underdiscussion and which the user may conveniently and automatically adjustthe height of the seat to an optimum height without knowledge of hisweight and without having to feel or sense any indicating devices.

The improved seat comprises a base which can be mounted on the floor ofan automotive vehicle, a seat member spaced from said base which ismovable up and down, i.e., away from and towards the base. A supportmeans is provided which is pivotly connected to said base and to saidseat means and which supports the latter in a substantially horizontalposition and movable 'toward and away from the base. Resilient means areprovided which act between the base and at least one of said precedingmeans for storing energy in response to a downward force applied to saidseat means and for applying a moment to said seat means whichcounteracts the downward force. Motor driven adjusting means areprovided which are connected to said resilient means for adjusting themovement applied by said resilient means to said seat means to maintainthe latter substantially at a predetermined distance from said baseregardless of the magnitude of said downward directed force. Means foractivating the adjusting means are provided, which also deactivate theadjusting means when said seat means is in said predetermined position.

According to a presently preferred embodiment, said means for activatingand deactivating the adjusting means comprises a cam member having aguide surface having an irregular portion. A switch member is providedhaving feeler means riding on said guide surface and sensing saidirregular portion, said two members being arranged so that movement ofsaid seat means over the operative range causes said feeler means tomove over substantially the entire guide surface. The switch memberopens to stop the motor of the adjusting means when the seat reaches aselected position.

Still referring to the presently preferred embodiment, said motor drivenadjusting means comprises spindle means connected to at least a, portionof said resilient means for moving the latter in relation to the pivotpoint about which said support means is pivoted on said base, wherebythe magnitude of said moment is moditied to equalize the downwardforces.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a fragmentary side elevationview (with certain parts broken away) of a seat which embodies thepresent invention; 1

FIG. 2 is a schematic representation of the power driven adjusting meansas well as the switch control means;

FIG. 3 is a side elevation view of another embodiment in accordance withthe present invention; and

FIG. 4 is a schematic representation of a power driven means and controlmeans similar to that shown in FIG. 2 but for the seat in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,and particularly FIG. 1 thereof, it will be seen that the arrangement ofthe present invention comprises adjustable seat means 1 which has asubstantially horizontal upper surface and serves to carry a cushion(not shown) as well as a customary back rest. Furthermore, it comprisesa base 4, which is mounted on the floor, of an automotive motor vehicle,and is connected with the adjustable seat means 1 by means of two pairof parallel links 2 and 3. The parts 1, 2, 3 and 4 together form aparallelogram arrangement whereby the adjustable seat means or upperseat means 1 moves upwardly or downwardly (while its upper surfaceremains substantially horizontally) when the links 2 and 3 are caused topivot, for example, during travel over rough terrain or bumpy road. Theupper end portions of the links 2 are fulcrummed in the upper seat means1, as at 5, and the lower end portions of these links are fulcrummed inthe base 4, as at 5'. The fulcrum 5' is a transverse horizontal shaftwhich is rigid with the links 2 so that it turns about its axis inresponse to movement of the upper seat means 1 towards and away from thebase 4. The fulcra for the upper and lower end portions of the links 3are respectively shown at 5a and 5a.

The shaft 5' is further rigidly connected with two downwardly extendedprojections or arms 6 which are located mainly in the interior of thebase 4 and can be integral with the links 2 because these links are alsofixed to the shaft 5. It will be seen that the composite link includingthe two links 2 and the two extensions 6 constitute a bell crank leverhaving a first arm articulately connected with the upper portion 1 and asecond arm confined in the interior of the base 1.

The median portions of the links 2 are articulately connected with theupper section 70 of a hydraulic or pneumatic shock absorber 7 whichfurther includes a second or lower section 7b articulately connectedwith the base 4, as at 7c. The sections 7a, 7b are movable relative toeach other in response to pivoting of the links 2 and serve to cushionthe upper seat portion during travel on uneven terrain. In theillustrated embodiment, the upper section 7a-of the shock absorber 7 hasa coupling pin 2a which is removably received in one of the severalpairs of registering holes or openings 2b provided in the link 2substantially midway between the fulcra 5 and 5'. By moving the couplingpin 2a into another pair of openings 11, the user can change thedistance between the shaft 5' and the point of.connection of the uppersection 7a to the links 2 to thereby change the moment or effort arm ofthe shock absorbers. If desired, the coupling pin 2a can be movedbetween an infinite number of positions by means ofa suitable adjustingmechanism so that it can be placed at any desired distance from theshaft 5'. A suitable adjusting mechanism may include a screw which isrotatably mounted between the links 2 so as to extend in a longitudinaldirection to these links, and a spindle nut which is provided in theupper end of section 7a and meshes with the screw so that it travelstowards or away from the shaft 5 in response to rotation of the screw bymeans of a wheel or the like.

The extensions 6 of the link 2 are provided with elongated guide slots 8which extend substantially or exactly radially of the shaft 5' andreceive two followers in the form of pins or trunnions provided on aspindle nut 9 which is disposed between the extensions 6 and meshes witha rotating screw or a spindle 10. The spindle nut 9 is provided orconnected with a short link 11 which is coupled to one end portion of atleast one helical spring 13 by means of a pin 12. The other end portionof the spring 13 is connected with the base 4. As shown, the right-handend portion of the spring 13, as viewed in FIG. 1, engages a horizontalpin 14 which is mounted in a bracket 15 of the base 4. The structurewhich is shown in the drawing preferably comprises two helical springs13, one on each side of the screw 10. Thus, the pin 12 may extend beyondboth sides of the link 11 and the left-hand end portions of the twosprings 13 are then connected to such pin at the opposite sides of thelink 11, The lower section 7b of the shock absorber 7 is preferablylocated between the two helical springs.

The screw or spindle 10 is rotatably mounted in transversely extendingbridge member 6a which connect the two extensions 6 to each other. Thescrew 14 is free to rotate but can not move axially so that the spindlenut 9 is compelled to move lengthwise of the slots 8 when the screw 10is caused to rotate by a mechanism including a set of bevel gears 16 anda shaft 17 which extends outwardly through an arcuate slot 18 providedin a sidewall 40 of the base 4. The outer end portion of the shaft 17(which is rotatably journalled in at least one of the extensions 6) isconnected to a motor 19 in order to rotate the feed screw 10 withattendant movement of the spindle nut 9 toward or away from the shaft 5.It will be understood that the gears 16, the shaft 17 and the motor 19participate in angular movement of the extension 6 about the axis of theshaft 5'.

The motor 19 can be selected to be of the DC or the AC type, although inaccordance with the presently preferred embodiment for such seats inmotor vehicles, the motor 19, as well as its associated circuitry, willbe described as being of the DC variety. More particularly, the motor 19is selected so that its direction of rotation can easily be reversed.

Referring to both FIG. 1 and 2, the embodiment under discussion furtherincludes an on-off switch 20, which is connected in series with a sourceof DC power suitable for the driving of the motor 19. The on-off switch20 can be conveniently located in the vehicle compartment, e.g., on thedash-board or on the side of the seat. Alternately, the on-off switch 20can be of a pressure sensitive type which is arranged underneath theseat cushion so that it is activated upon an occupant being seated inthe seat.

The subject embodiment shown in FIG. 1, includes further a switch memberin the form ofa stop switch 21 which is mounted on one of the downwardlyprojecting extensions 6 to automatically turn off the motor when apreselected optimum position of the adjustable seat means 1 has beenachieved. To accomplish this automatic selection, a cam member 22, whichis in the form of an elongated arcuate section having a substantiallysmooth cam surface which faces the switch member 21, is mounted rigidlyto the sidewall 4a of the base 4. The cam member 22 is provided, in thiscam surface, with an irregular portion or cut-out 23 which forms aninward recess in the cam surface. The cam member 22 is further providedwith a pair of elongated positioning slots 24 which, in cooperation witha pair of set screws 25, permits the adjustment of the position of thecam member 22 along the path of travel of the bridge member 6a of thedownwardly projecting extensions 6. In this manner, it is possible toposition the cut-out 23 at a preselected position along acircumferential path about the transverse horizontal shaft 5'. Theswitch member 21 is normally closed to thereby connect the negativeterminal of the source of power to the motor 19. However, when thefeeler means 21a of the switch member 21 passes over the cut-out 23, thefeeler means moves into the same to thereby open the switch member 21and disconnect'the supply of energy to motor 19. Thus, it is clear, thatwhen the feeler means 21a is in contact with the cut-out 23, the motor19 is necessarily deactivated. I

Preferably, the elongated positioning slots 24 are sufficiently long topermit the positioning of cam member 22 over a wide range of positionsso that when the adjustable seat means 1 moves over its operative range,e.g., from its uppermost possible position to its lowermost possibleposition, the bridge member 6a, as well as the feeler means 21a, movebetween the two ends of the cam member 22. In order to permit theselection of any of the positions of the operative range of theadjustable seat means 1 as the optimum or desired or preselectedposition, it is necessary that the cutout 23-bepositioned so that thefeeler means 21a and the cut-out 23 engage in the optimum position.However, it is not a critical feature of the present invention that cammember 22 be made movable to permit selection of any position of theseat means 1. In many instances a more restricted range may beacceptable since the desired preselected optimum position of theadjustable seat means lwill be an intermediate or median position oranother position which is within a small range of this median position.

As described above, the spindle nut 9, the short link 11 as well as thepin 12 are movable between the downward projecting extensions 6 towardsand away from the transverse horizontal shaft 5' in response to therotation of the spindle feed screw 10. The movement along the screw issubstantially between the two ends of the screw 10, Le, between theregion of the bevel gears 16 and the region of the bridge member 6a.

In order to protect the motor 19'as well as to provide ing spindle andthe correspondingswitch 26 is activated to change the direction ofrotation of the motor 19. Referring to FIG. 2, the switches 26 are ofadoublepole, double throw variety. The common contacts of both poles ofone of the switches26 is connected to a terminal of the on-off switch20. On the other hand, the common contacts of each of the poles of theother switch 26 is connected to another one of the inputs of the motor19. The circuit arrangement for accomplishing the motor reversal is notcritical to the present invention, as many other circuits may beutilized for that purpose. However, FIG. 2 shows-the possible wiringarrangement between the switches 26 and motor 19. In the schematic, thefeed screw 10 is shown to extend between the two feeler means 26a whichextend beyond the short link 11, the latter being movable from one endof the rotatable feed screw to the other end to thereby engage one orthe other of the means 26a. With the condition of the switches. 26 asshown, and with the on-off switch 20 closed, and the feeler means 21ariding on the surface of the cam 22, a current will be delivered only toone of the input terminals of the motor. The current in this case willpass through the two right-hand poles of each of the reversing switches26.

Accordingly, the short link 11 will move in one of the directions alongthe screw 10. If the direction of rotation of motor 19 is such as tocause the feeler means 21a to move away from the cut-out 23, the shortlink 11 will ultimately reach one end of the screw 10 and contact withthe corresponding feeler means 26a. The reversing switches are soarranged that the contacting of either one of the feeler means 26acauses the current to flow into another one of the input terminals ofmotor 19 to thereby reverse the direction of the motor. With thedirection of rotation of the motor in reverse, the feeler means 21a nowmoves towards the cut-out 23, as it may have done originally if one ofthe reversing switches 26 had initially been in a different position. Asexplained above, as soon as the feeler means 21a extends into thecut-out 23 this opens the supply circuit to the motor 19 and furthermovement of the short link 11 ceases.

The aforementioned, but not illustrated adjusting means for moving thecoupling pin 2a of the upper section of the shock absorber 7a between aninfinite number of positions may include a feed screw similar to thefeed screw 10 and a spindle nut which carries the coupling pin 2a and isanalogous to the spindle nut 9. A hand wheel for rotating the feed screwof the adjusting means for the coupling pin 2a can be located at theexposed surface of the front wall 4b, or the screw may be motor drivenby a motor similar to motor 19.

As suggested above, the embodiment shown in FIG. 1 permits an optimumposition of the adjustable seat means 1 to be achieved automatically andwithout knowledge of the occupants weight. By adjusting the position ofthe cam member'22 relative to the position of the stop switch or switchmember 21, the short link 11 moves in an upward or downward directionalong the screw 10 so as to change the moment arm about which thehelical spring 13 acts about the transverse shaft 5'.

The operation of the embodiment as shown in FIG. 1 and 2 will now bedescribed-With the cam member 22 adjusted to provide an intermediateoptimum position of the adjustable seat means I, the occupant sitsthereon and the on-off switch 20 is either manually or automaticallyclosed. The weight of the occupant causes the adjustable seat means 1 tomove in a downward direction, and, therefore, causes the downwardlyprojecting extensions 6 as well as switch 21 to move in a clockwisedirection about the transverse horizontal shaft 5'. With the spindle nut9in an initial position along the screw 10, the spring l3 will betensioned so as to provide a moment about the transverse shaft 5' tocounteract the downward force applied to the adjustable seat means 1. Anequalibrium or steady state point will be reached when the downwardforce applied by the weight of the occupant is fully counteracted by themoment of the helical spring in a counterclockwise direction about thetransverse shaft If the weight of the occupant is such that the feelermeans 21a will be in the cut-out 23, the motor 19 will not be activatedsince an equalibrium condition exists. On the other hand, if the weightof the occupant is greater or less than the weight which would causesuch meeting of the feeler means 210 and the cutout 23 for an initialposition of the short links 11, the feeler means 21a will be locatedalong the guide surface of the cam member 22 either before or beyond thecut-out 23 respectively. In this case, the switch member 21 remainsclosed and the motor 19 rotates in one direction or another depending onthe initial settings of the reversing switches 26. As described above,should motor 19 begin to rotate in a direction to cause the feeler means21a to move directly towards the cut-out 23, then the adjustable seatmeans will move initially towards the optimum position and stop in thatposition when the feeler means 21a engages the cut-out 23. On the otherhand, should the direction of rotation of the motor 19 be such that thefeeler means 210 moves away from the cut-out 23 and towards one of theend positions of the feed screw 10, then the adjustable seat means 1will initially move away from the optimum position until the directionof the motor 19 is reversed in response to the short link.

11 coming into contact with one of the feeler means 26a at the end ofthe screw travel. At such time, the feeler means 210 will again movetoward the direction of the cut-out 23 and the motor 19 will stop whenengagement is entertained as described above. It is clear from the abovedescription that the counteracting moment which is provided by thehelical spring 13, as well as that provided by the shock absorber 7, canbe easily adjusted by changing the length of the moment arms about thetransverse shaft 5' along one of the arms of the bell crank which isformed by the downwardly projecting extensions 6 and the links 2.

Referring now to FIG. 3, there is shown another embodiment of thepresent invention wherein the adjustable seat means 1 is again mountedfor movement on the base 4 by means of a pair of coupling links 2 and 3.In this embodiment, links 2 are connected to the adjustable seat means 1about a coupling pin 27. A U- shaped bracket 28 is fixedly'mountedwithin the base 4. Elements in the embodiment shown in FIG. 3 which arethe same as those shown in FIG. 1 are given the same reference numerals,while those which serve the same function are designated by the primedequivalents of the reference numerals utilized in FIG. 1. Thus, thebracket 28 is provided with a pair of guide slots 8' which are directedin a substantially circumferential direction of the coupling pin 27. Inthe present embodiment, the spindle nut 9 is connected to the screw 10'and to a short link 11. The short link 11 is connected to a pin 12'which extends through the slot 8' of bracket 28.

The shock absorber 7 as Well as the helical springs 13' are connectedbetween the pin 12' and the pin 27. The helical springs 13 and the shockabsorber 7 can be mounted coaxially or adjacent and parallel to oneanother between the pins 12' and 27.

The screw 10', as in the previous embodiment, is motor driven by a motor19 which is connected to the screw 10' by means of a coupling 29, e.g.,a universal joint. It will be noted that the screw 10' is substantiallyparallel to the guide slots 8' so that the distance between the pin 12and the spindle nut 9' is always the same and the short link 11 therebyalways moves in a direction parallel to the guide slot 8 but it alwaysremains perpendicular to direction of travel.

In the present embodiment, the helical springs 13' as well as shockabsorber 7 acts between the coupling pins 27 and 12'. At the lower endsof these respective resilient members, the helical spring 13' and shockabsorber 7 act against the lower edges of the guide slots 8, the forceexerted against the bracket 28 being in a direction substantiallyperpendicular to the direction of the slots 8. At the other ends of theresilient means, the helical spring 13 and shock absorber 7 act againstthe pin 27, the direction of the forces exerted against the pin 27 beingvariable by the movement of the pin 12' along the guide slots 8. Thecounterclockwise moment about the transverse shaft 5, which opposes thedownward forces applied to the adjustable seat means 1, can be modifiedin the present embodiment by changing the direction of the force appliedto the pin 27. The moment arm for the counteracting moment is equal tothe length of the link 2, namely, the distance between the shaft 5 andthe coupling pin 27. Thus, the moment arm for the seat means remains thesame, and only the effective force component normal to the link 2 ischanged by changing the direction of the forces applied to pin 27.

As in the embodiment shown in FIG. 1, cam member 22 has a cut-out 23 andelongated positioning slots are provided for the purpose describedabove. Switch 21 is rigidly mounted on the sidewall 4a of the base 4 andthe cam member 22 is mounted for movement with the link 3 so that thecam member 22 has its guide surface scanned as the adjustable seat means1 moves between extreme positions. It will thus be noted that it is notcritical for purposes of this invention whether cam member 22 or switchmember 21 is rigidly fixed or, respectively, movably mounted, it onlybeing important that one of said members be mounted for movement and oneis rigidly fixed so that one may move relative to the other withmovement of the adjustable seat means 1 so that the feeler means 21a mayride over almost the entire guide surface of cam 22.

As in the embodiment described in FIG. 1, a pair of switches 30 arepositioned at each end of the guide slots 8' to sense when the elementsmovable along the feed screw 10' have reached one of the ends of theguide slots 8'. Referring both to FIGS. 3 and 4, it will be noted thatin accordance with this second embodiment, the switches 30 are of thenormally closed type. An additional set of actuating switches 20 and 20"are mounted on the front wall 4b of the base 4 in a convenient locationto the occupant of the seat, or the latter switches can also be mountedon the dashboard of the vehicle. The actuating switches 20' and 20" canbe selected to be single-pole, single-throw switches or, preferably,they are selected to be momentary contact switches. Each actuatingswitch 20' or 20" is associated with one direction of rotation of themotor 19. Thus, when the switch member 21 is closed, and, for example,actuating switch 20' is depressed, a current will flow through theright-hand switch 30, as shown in FIG. 4, to one terminal of the motor19'. On the other hand, if the actuating switch 20" is closed, then thecurrent will flow through the right-hand switch 30 to another terminalof the motor 19'. With this arrangement, an appropriate direction of therotation of motor 19 may be selected so that the feeler means 21aimmediately moves towards the cut-out 23. In this manner, the optimumposition of the adjustable seat means 1 is directly and more quicklyachieved than with the embodiment shown in FIG. 1 where, in certaininitial settings of the reversing switches 26, it is possible that thefeeler means 210 initially moves away from the cutout 23.

Referring to FIG. 4, it will be noted that'when the short link 11arrives at one of the end positions of the feed screw 19, it will actupon a corresponding feeler means 300 which will have the. effect ofopening therespective normally closed switch 30. The actuating switches20, 20" and the normally closed switches 30 are so arranged so that theshort link lll moves towards the normally closed switch 30 which is incircuit with the actuated switch 20' or 20f. In this manner, the motor19 is protected when one of the actuating switches 20, 20" is maintainedin a depressed position since the short link 11 automatically opens upthe circuit of the actuated switch 20' or 20" to thereby prevent furtherenergization of the motor 119.

With the embodiment as shown in FIG. 3, it is possible to select aposition other than the pre-adjusted or preselected optimum positionshould the occupant so desire it. One of the switches 201 or 20" isdepressed until the desired position of the adjustable seat means 1 isattained and then the actuating switch is released.

To distinguish the actuating switches 20, 20", these two switches can beprovided with knobs of different shapes and/or colors. Preferably, theshapes of the two actuating switches are substantially different thatthey may be recognized by merely touching the same without the necessityof looking at the switches. This is accomplished in the embodiment asshown in FIG. 3 by providing a large knob associated with the switch 20"and a relatively small knob associated with the actuating switch 20.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofseats differing from the types described above.

While the invention has been illustrated and described as embodied inautomatically adjustable seats, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should-and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended:

1. In a seat, particularly for use in an automotive vehicle, acombination comprising a base; seat means spaced from said base; supportmeans pivotally connected to said base and said seat means andsupporting the latter in a substantially horizontal position and movabletoward and away from said base; resilient means acting between said baseand at least one of said preceding means for storing energy in responseto a downward force applied to said seat means and for applying a momentto said seat means counteracting said downward force; motor drivenadjusting means connected to said resilient means for adjusting themoment applied by said resilient means to said seat means to maintainthe latter substantially at a predetermined distance from said baseregardless of the magnitude of said downwardly directed force; and meansfor activating said adjusting means when said seat means moves under theinfluence of said force away from said predetermined position and fordeactivating said adjusting means when said seat means is in saidpredetermined position.

2. A combination as defined in claim ll, wherein said means foractivating and deactivating said adjusting means comprises a cam memberhaving a guide surface having an irregular portion; and a switch memberhaving feeler means for riding on said guide surface and sensing saidirregular portion, said two members being arranged so that movement ofsaid seat means over the operative range causes said feeler means toride over substantially the entire guide surface.

3. A combination as defined in claim 2, further including circuit meansconnected to said switch member and to said motor drive adjusting means,said switch member opening said circuit means in response to said feelermeans contacting said irregular portion, to

thereby deactivate said adjustingmeans.

4. A combination as defined in claim 3, wherein said motor drivenadjusting means comprises spindle means connected to at least a portionof said resilient means for moving the latter in relation to a pivotpoint about which said support means pivots about said base; and motormeans coupled to said spindle means for causing the latter to move saidresilient means portion, whereby the magnitude of said moment ismodified to equalize said downward force.

5. A combination as defined in claim 2, wherein one of said members isfixedly mounted on said base while the other member is mounted on one ofsaid prior mentioned preceding means for sharing the movements thereof.

6. A combination as defined in claim 4, and including a electromotordriving said spindle means, said spindle means being arranged to movesaid resilient means portion between first and second positions whichrespectively correspond to the end'positions of the operative range ofpositions of said seat means above said base, and further comprising apair of reversing switches respectively positioned at said first andsecond positions for sensing when said portion: has reached thecorresponding position, said reversing switches being connected to saidcircuit means and each arranged to change the direction of current flowthrough said electric motor, whereby said motor means is reversed in itsdirection of rotation when one of said positions has been reached.

7. A combination as defined in claim 6, further comprising an on-offswitch connected in said circuit means.

8. A combination as defined in claim 4, and including an electromotordriving said spindle means, said spindle means being arranged to movesaid resilient means between first and second positions whichrespectively correspond to the end positions of the range of positionsof the operative range of said seat means above said base, and furthercomprising a pair of normally closed switches, said switches opening inresponse to said portion reaching one of said positions; and a pair ofactuating switches each connected to another of said normally closedswitches, said circuit means being arranged between said four switchesso that the closing of each of the actuating switches causes saidelectromotor to urge said portion, through said spindle means, to moverespectively in the direction of the closed actuated switch.

9. A combination as defined in claim 2, wherein said cam member has asubstantially smooth surface, and wherein said irregular portioncomprises a cut-out portion, said feeler means comprising a roller whichrolls on said smooth surface and enters said cut-out portion when saidseat means is positioned at a predetermined spacing above said base tothereby open said switch member and prevent the energization of saidmotor driven adjusting means.

10. A combination as defined in claim 2, wherein at least one of saidmembers include adjustable positioning means for moving said at leastone member. relative to the other to thereby preselect an optimumspacing of said seat means above said base at which point said feelermeans contacts said irregular portion.

11. A combination as defined in claim 1, wherein said support meanscomprises at least one bell-crank, and said resilient means comprises abiassing spring connected to said base and adjustably connected to onearm of said bell-crank, and a shock absorber connected to said base andadjustably connected to the other arm of said bell-crank.

12. A combination as defined in claim 11, wherein said motor drivenadjusting means comprises a motor driven spindle rotatably mounted onsaid one arm, and coupling means connecting said spindle with saidbiassing means for longitudinal movement along said spindle in responseto rotation of said spindle.

13. A combination as defined in claim 1, wh'erein said resilient meanscomprises a biassing spring, and a shock absorber mounted coaxially withthe latter, these elements being connected at one of their ends to thepivot point about which said seat means pivots about said support means.

14. A combination as defined in claim 13, further comprising at leastone bracket having a guide slot extending substantially perpendicularlyto the direction of the axis of said pivot point; said motor drivenadjusting means comprises a spindle rotatably mounted and extendingalong said guide slot; and coupling means for connecting said spindle tosaid biassing spring and cooperatively engaged in said slot to therebyguide said coupling means in response to rotation of said spindle, saidbiassing spring acting between said pivot point and said coupling meansto generate a force passing through said pivot point in a predetermineddirection, said portion being movable from one end of the guide slot tothe other end thereof in response to rotation of said spindle, wherebythe direction of the force of said spring is changed to thereby modifysaid counteracting moment.

1. In a seat, particularly for use in an automotive vehicle, acombination comprising a base; seat means spaced from said base; supportmeans pivotally connected to said base and said seat means andsupporting the latter in a substantially horizontal position and movabletoward and away from said base; resilient means acting between said baseand at least one of said preceding means for storing energy in responseto a downward force applied to said seat means and for applying a momentto said seat means counteracting said downward force; motor drivenadjusting means connected to said resilient means for adjusting themoment applied by said resilient means to said seat means to maintainthe latter substantially at a predetermined distance from said baseregardless of the magnitude of said downwardly directed force; and meansfor activating said adjusting means when said seat means moves under theinfluence of said force away from said predetermined position and fordeactivating said adjusting means when said seat means is in saidpredetermined position.
 2. A combination as defined in claim 1, whereinsaid means for activating and deactivating said adjusting meanscomprises a cam member having a guide surface having an irregularportion; and a switch member having feeler means for riding on saidguide surface and sensing said irregular portion, said two members beingarranged so that movement of said seat means over the operative rangecauses said feeler means to ride over substantially the entire guidesurface.
 3. A combination as defined in claim 2, further includingcircuit means connected to said switch member and to said motor driveadjusting means, said switch member opening said circuit means inresponse to said feeler means contacting said irregular portion, tothereby deactivate said adjusting means.
 4. A combination as defined inclaim 3, wherein said motor driven adjusting means comprises spindlemeans connected to at least a portion of said resilient means for movingthe latter in relation to a pivot point about which said support meanspivots about said base; and motor means coupled to said spindle meansfor causing the latter to move said resilient means portion, whereby themagnitude of said moment is modified to equalize said downward force. 5.A combination as defined in claim 2, wherein one of said members isfixedly mounted on said base while the other member is mounted on one ofsaid prior mentioned preceding means for sharing the movements thereof.6. A combination as defined in claim 4, and including a electromotordriving said spindle means, said spindle means being arranged to movesaid resilient means portion between first and second positions whichrespectively correspond to the end positions of the operative range ofpositions of said seat means above said base, and further coMprising apair of reversing switches respectively positioned at said first andsecond positions for sensing when said portion has reached thecorresponding position, said reversing switches being connected to saidcircuit means and each arranged to change the direction of current flowthrough said electric motor, whereby said motor means is reversed in itsdirection of rotation when one of said positions has been reached.
 7. Acombination as defined in claim 6, further comprising an on-off switchconnected in said circuit means.
 8. A combination as defined in claim 4,and including an electromotor driving said spindle means, said spindlemeans being arranged to move said resilient means between first andsecond positions which respectively correspond to the end positions ofthe range of positions of the operative range of said seat means abovesaid base, and further comprising a pair of normally closed switches,said switches opening in response to said portion reaching one of saidpositions; and a pair of actuating switches each connected to another ofsaid normally closed switches, said circuit means being arranged betweensaid four switches so that the closing of each of the actuating switchescauses said electromotor to urge said portion, through said spindlemeans, to move respectively in the direction of the closed actuatedswitch.
 9. A combination as defined in claim 2, wherein said cam memberhas a substantially smooth surface, and wherein said irregular portioncomprises a cut-out portion, said feeler means comprising a roller whichrolls on said smooth surface and enters said cut-out portion when saidseat means is positioned at a predetermined spacing above said base tothereby open said switch member and prevent the energization of saidmotor driven adjusting means.
 10. A combination as defined in claim 2,wherein at least one of said members include adjustable positioningmeans for moving said at least one member relative to the other tothereby preselect an optimum spacing of said seat means above said baseat which point said feeler means contacts said irregular portion.
 11. Acombination as defined in claim 1, wherein said support means comprisesat least one bell-crank, and said resilient means comprises a biassingspring connected to said base and adjustably connected to one arm ofsaid bell-crank, and a shock absorber connected to said base andadjustably connected to the other arm of said bell-crank.
 12. Acombination as defined in claim 11, wherein said motor driven adjustingmeans comprises a motor driven spindle rotatably mounted on said onearm, and coupling means connecting said spindle with said biassing meansfor longitudinal movement along said spindle in response to rotation ofsaid spindle.
 13. A combination as defined in claim 1, wherein saidresilient means comprises a biassing spring, and a shock absorbermounted coaxially with the latter, these elements being connected at oneof their ends to the pivot point about which said seat means pivotsabout said support means.
 14. A combination as defined in claim 13,further comprising at least one bracket having a guide slot extendingsubstantially perpendicularly to the direction of the axis of said pivotpoint; said motor driven adjusting means comprises a spindle rotatablymounted and extending along said guide slot; and coupling means forconnecting said spindle to said biassing spring and cooperativelyengaged in said slot to thereby guide said coupling means in response torotation of said spindle, said biassing spring acting between said pivotpoint and said coupling means to generate a force passing through saidpivot point in a predetermined direction, said portion being movablefrom one end of the guide slot to the other end thereof in response torotation of said spindle, whereby the direction of the force of saidspring is changed to thereby modify said counteracting moment.